The bags look simple enough — two polyethylene sacks placed one inside the other. Since 2007, this revolutionary Purdue University invention has enabled millions of farmers in sub-Saharan Africa to store their crops for up to a year after they are harvested, rather than see them spoil or be devoured by pests.

Now a $10 million grant from the Bill and Melinda Gates Foundation will enable Purdue researchers to add a third outer bag to the hermetically sealed invention and extend its usefulness to more subsistence farmers.

The Purdue Improved Crop Storage bags, developed by professor Larry Murdock of the Department of Entomology, are crop-saving bags that protect and store crops such as corn, common beans, wheat, peanuts, pigeon pea, mungbean and sorghum. The technology helps improve food availability and increases the income, because farmers who use the bags no longer need chemicals to control pests.

The next phase of the project involves the addition of a woven bag outside the two polyethylene bags, which adds enough strength to allow the bags to bear more weight and be transported. Thus, heavier grains also can be protected.

"We found that two bags were sufficient for protection, but we also found that a bag full of grain could be quite heavy and it often has to be moved," Murdock said. "That's probably the biggest change (since the start of the project), was the addition of the woven bag to the outside."

PICS technology was developed in the late 1980s by Purdue faculty, students, staff and partners in northern Cameroon with funding from the U.S. Agency for International Development, said Jess Lowenberg-DeBoer, associate dean and director of IPIA/Professor of Ag Econ.

"Their funding ran out in the early 90s, so Dr. Murdock and I wrote numerous proposals to try to find funding to get the technology out to people," Lowenberg-DeBoer said.

A PICS bag holds grain ready to sale or storage for more than one year.(Photo: Dieudonne Baributsa/Purdue International Programs in Agriculture)

Efforts under the initial PICS program, which began in 2007, focused on using the technology to store cowpea — a legume known in the U.S. as black-eyed pea — in West and Central Africa. Later, a second phase involved research into how the bags could be used to store other crops.

"PICS bags being used in much of Africa are being manufactured in African cities," Murdock said. "This creates jobs and helps enable a stable supply chain."

The bags not only help provide income to farmers, who will have the ability to sell their crops throughout the year, but also business opportunities for private companies in Africa. This could lead to the creation of additional jobs in manufacturing and retail in rural areas, Murdock said. Extending the program to other countries also is under consideration.

"We know the technology works for many other crops as well, but we've really focused on involvement in several African countries for now," Murdock said. "In terms of Asia, there has been work begun and is still in progress in Afghanistan in storing wheat and legumes."

"I think this is a great example of what's talked about at Purdue as discovery with delivery." Lowenberg-DeBoer said. "Not only did faculty and students help to create the technology, but they were also out there helping to get it out to people in rural parts of Africa and finding ways to keep the supply chain going."

Local farmers seal PICS bags shut to store crops for up to one year.(Photo: Dieudonne Baributsa)